The importance of documentation and contracts in back-end development across multiple teams

🇺🇸 English Version:

Today I had a valuable realization while working on back-end development with Java and Spring Boot: the critical role of well-documented APIs and well-defined contracts.

🤝 Multi-team integration demands clarity

In my current environment, it's common to have multiple teams working in parallel, whether developing microservices or micro-frontends, all consuming or exposing the same API endpoints.

That’s why having a clear and updated contract is vital. It ensures everyone involved knows:

What data is expected in requests (input)
What data will be returned (output)
Available HTTP methods (GET, POST, PUT, DELETE)
Possible response statuses (200, 400, 500, etc.)

📜 Example of a JSON contract

When building endpoints, we clearly document their inputs and outputs. Example:

🔽 Request

POST /api/user
{
  "name": "Maria",
  "email": "maria@email.com",
  "age": 25
}

Simple, but this defines a JSON contract that any other team (front-end or back-end) can rely on.

📘 Tools that support API documentation

Swagger/OpenAPI: Generates interactive documentation

Postman: Simulates and shares requests

SpringDoc: Integrates easily with Spring Boot and Swagger

🎯 Best practices for documentation

Keep documentation up-to-date with any contract changes

Use automated tests to validate contracts (e.g., JSON Schema)

Version your APIs to avoid breaking changes

💬 This insight came from a real-world challenge where I had to sync with another front-end team. Documentation played a central role in the success of the delivery.

📌 If you're new to back-end development, remember: documenting is just as important as coding.